This invention is directed to a dental prosthesis substructure wherein the substructure has a reduced metallic body volume for economy, increased ceramic bonding area for secure ceramic structure and increased vertical loading strength so that it can withstand normal forces without bending and breaking the porcelain.
Most prior art dental prosthesis substructures have followed the configuration of nature. Molds are taken of the original tooth shape, and these shapes are reduced in size to accommodate the equivalent of porcelain surface. In this way, a prosthesis having substantially the original tooth configuration is produced. The problems of such prostheses include the fact that there is a large volume of substructure metal therein. This metal is expensive, and as a consequence, the dental restoration can be reduced in cost by reducing the volume of metal therein. In addition, the original configuration is not the best as far as strength is concerned. The force loadings on the original teeth are almost directly from the occlusal surfaces through the root into the jaw bone. However, in a prosthesis, especially one for several teeth, the occlusal loads are transmitted laterally across the prosthesis to the ends, in the case of a bridge. The original tooth shape configuration is not an optimum shape for transmitting these loads in that direction.
U.S. Pat. No. 4,231,740 to Shoher, et al. teaches a dental metal substructure composed of a framework of relatively thin metal members interconnected to form concavities. Porcelain fills and surrounds the network. While the patent speaks of configuring the framework to be sufficiently rigid for the purpose, it has been found that the open network substructure is not sufficiently strong for bridgework and the like. Furthermore, the open interior makes it difficult to apply the ceramic to the desired final configuration. Thus, this open network substructure has not been successful.
Thus, there is need for a prosthesis substructure of specific design to provide adequate vertical loading strength with a reduced body volume.